CA1306716C - Catalytic hydrodewaxing process - Google Patents
Catalytic hydrodewaxing processInfo
- Publication number
- CA1306716C CA1306716C CA000580804A CA580804A CA1306716C CA 1306716 C CA1306716 C CA 1306716C CA 000580804 A CA000580804 A CA 000580804A CA 580804 A CA580804 A CA 580804A CA 1306716 C CA1306716 C CA 1306716C
- Authority
- CA
- Canada
- Prior art keywords
- zsm
- zeolite
- bound
- refractory oxide
- low acidity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J29/00—Catalysts comprising molecular sieves
- B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
- B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
- B01J29/65—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the ferrierite type, e.g. types ZSM-21, ZSM-35 or ZSM-38, as exemplified by patent documents US4046859, US4016245 and US4046859, respectively
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
- C10G45/00—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds
- C10G45/58—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to change the structural skeleton of some of the hydrocarbon content without cracking the other hydrocarbons present, e.g. lowering pour point; Selective hydrocracking of normal paraffins
- C10G45/60—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to change the structural skeleton of some of the hydrocarbon content without cracking the other hydrocarbons present, e.g. lowering pour point; Selective hydrocracking of normal paraffins characterised by the catalyst used
- C10G45/64—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to change the structural skeleton of some of the hydrocarbon content without cracking the other hydrocarbons present, e.g. lowering pour point; Selective hydrocracking of normal paraffins characterised by the catalyst used containing crystalline alumino-silicates, e.g. molecular sieves
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2229/00—Aspects of molecular sieve catalysts not covered by B01J29/00
- B01J2229/10—After treatment, characterised by the effect to be obtained
- B01J2229/20—After treatment, characterised by the effect to be obtained to introduce other elements in the catalyst composition comprising the molecular sieve, but not specially in or on the molecular sieve itself
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2229/00—Aspects of molecular sieve catalysts not covered by B01J29/00
- B01J2229/10—After treatment, characterised by the effect to be obtained
- B01J2229/26—After treatment, characterised by the effect to be obtained to stabilize the total catalyst structure
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2229/00—Aspects of molecular sieve catalysts not covered by B01J29/00
- B01J2229/30—After treatment, characterised by the means used
- B01J2229/42—Addition of matrix or binder particles
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J29/00—Catalysts comprising molecular sieves
- B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
- B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
- B01J29/40—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J29/00—Catalysts comprising molecular sieves
- B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
- B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
- B01J29/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65
Abstract
ABSTRACT
CATALYTIC HYDRODEWAXING PROCESS
The catalytic hydrodewaxing of a waxy hydrocarbon oil to provide a lube product of high viscosity index is carried out employing an extruded low acidity refractory oxide-bound intermediate pore size zeolite catalyst composition such as silica-bound ZSM-35.
CATALYTIC HYDRODEWAXING PROCESS
The catalytic hydrodewaxing of a waxy hydrocarbon oil to provide a lube product of high viscosity index is carried out employing an extruded low acidity refractory oxide-bound intermediate pore size zeolite catalyst composition such as silica-bound ZSM-35.
Description
F-4513 iL3C~6 ~6 CATALYTIC HYDRODEWAXING PROCESS
This invention relates to a process for ~he catalytic hydrodewaxing of a waxy hydrocarbon oil to provide a lubricating oil of high viscosity index (V.I.) The invention is specifically directed to a process for catalytically hydrodewaxing a waxy distillate lubricating oil utilizing a low acidity refractory oxide-bo~d intermediate pore size zeolite, e.g., silica-bound ZSM-5 or silica-bound ZSM~35, to obtain a lubricating oil of low pour point and of high V,I, Refining suitable petroleum crude oils to obtain a variety of lubricating oils which function effectively in diverse environments has become a highly developed and complex art.
Although the broad principles involved in refining are qualitatively understood, the art is encumbered by quantitatiYe uncertainties which require considerable resor-t to empiricism in practical practical refining. Underlying these quantitative uncertainties is the complexity of the molecular constitution of lubricating oils.
Because lubricating oils for the most part are based on petroleum fractions boiling above about 232C (450F), the molecular weight of the hydrocarbon constituents is high and these constituen~s display almost all conceivable structure types. lhis complexity and its consequences are referred to in we11 known treatises, such as, for example, in "Petroleum Refinery Engineering,'7 by WoL~ Nelson, ~cGraw Hill Book Company, IncO, ~ew York, N~Y~s 1958 (Fourth Edition).
In general, the basic premise in lubricant refining is that a suitable crude oil, as shown by experience or by assay, contains a quantity o lubricant stock having a predetermined set of properties ~3~ 7 3L~
such as, for example, appropriate viscosity, oxidation stability, and ~aintenance of fluidity at low temperatures. The process of refining to isolate that lubricant stock consists of a set of subtractive unit operations which removes the unwanted components.
The most important of these unit operations include distillation, solvent refining, and dewaxing, which basically are physical separation processes in the sense that if all the separated fractions were recombined one would reconstitute ~he crude oil.
A refined lubricant stock may be used as such as a lubricant, or it may be blended with another refined lubricant stock having different properties. Or, the refined lubricant stock9 prior to use as a lubricant, may be co~pounded with one or more additives which function~ for example, as antioxidants, extre~e pressure additives, and V.I. improvers.
For the preparation of a hi~h ~rade distillate lubricating oil stock, the current practice is to vacuum distill an atmospheric tower residuum from an appropriate crude oil as the first step.
This step provides one or more raw stocks within the boiling ran~e of about 232C (450) to 566C (1050F) Ater preparation of a raw stock of sui-table boilin~ range, it is extracted with a solvent, e.g., furfural, phenol, sulfalane, or chlorex7 which is selective for aromatic hydrocarbons, and which reinoves undesirable components. The raffina-te from solvent refining is then dewaxed, for example by ad~ixing with a solvent such as a blend of methyl ethyl ketone and toluene. The mixture is chilled to induce crystallization of the paraffin waxes which are then separated from the raffinate. Sufficient quanti~ies of wax are removed to provide the desired pour point for the raffinate.
Other processes such as hydrofinishing or clay percolation may be used if needed to reduce the nitrogen and sulfur conten~s or improve the color of the lubricating oil stock.
Viscosity index (V.I.) is a quality parameter of considerable importance Eor distillate lubricating oils to be used F-4513 ~~3~~
in aUtQmotiVe engines and aircraft engines which are subject to wide variations in temperature. This Index indicates the rate of change of viscosity with temperature. A high viscosity lndex of 100 indicates an oil that does not tend to become viscous at low temperatures or become thin at hi~h temperatures. ~asuremen~ of the Saybolt Uhiversal Viscosity of an oil at 54 (130) and 38~C
(~00F), and referral to correlations, provides 3 measure of the V.I. of the oil. For purposes of the present invention, whenever V.I. is referred to it is meant the V.I. as noted in the Viscosity Index tabulations of the ASI~I (D567), published by AST~, 1916 Race St., Philadelphia 3, Pa., or equivalent.
To prepare high V.I. automotive and aircraft oils the refiner usually selects a crude oil relatively rich in paraffin hydrocarbons, since experience has shown that crudes poor in paraffins, such as those commonly termed "naphthene base" crudes, yield little or no refined stock having a V I. above about 40.
Suitable st^cks for high V.I. oils, however, also contain substantial quantities of w~xes which result in solvent-refined lubricating oil stocks of high pour point. Thus, in general9 the refining of crude oil to prepare acceptable high V.I. distillate stocks ordinarily includes dewaxing to reduce the pour point~
In recent years, catalytic techniques have become available for dewaxing of petroleum stocks. Catalytic dewaxing9 unlike prior-art dewaxing processes, although subtractive, is not a physical process but ra-ther depends on transforming the straight chain and other waxy paraffins to nonwax materials. The process, however9 is ~ore economical and thus of industrial interest even thou~h at leas~ some loss of se~lable wax is inherent. Com~ercial interest in catalytic dewaxlng is evidence of the need for more 3~ efficient refinery processes to produce low pour point lubricantsO
UOS. Reissue Patent No. 28~398 describes a process for catalytic dewaxing with a catalyst comprising zeolite ZSM-5~ Such a process combined with catalytic hydrofinishing is described in VOS~
~3~P6~7~6 Patent No. 3,894,938. U.S~ Patent No. 3,755,138 describes a process for mild solvent dewaxing to remove hi~h quality wax from a lube stock, which is then catalytically dewaxed to specification pour point. U.S. Patent No. 4,2229855 describes dewaxing operations to produce lubricating oils of low pour point and of high V.I~
utilizin~ a special class of zeolites which includes ZSM-23 and ~SM~35.
U.S. Patent No. 4,247,388 describes dewaxing operations utilizing ZSM'5 type zeolites of specific activity.
U.S. Patent No. 4,372,839 describes a catalytic dewaxing process employing two different zeolites such as ZSY~5 and ZSM-35.
U.S. Patent No. 4,5829815 describes a method for prep~ring a silica-bound zeolite of improved crush stren~th relative to other silica-rich zeolites. Accordin~ to this method, a ~ixture of silica and a zeolite su~h as ZSM~4 (Omega), ZSM-5, ZS~-ll, ZSM-12, ZSM-23, ZS~-35, ZSM-38, ZSM-48, ~eta, X, Y, L, ferrierite, ~ordenite, dachiardite, clinoptilolite, offretite, erionite, ~melinite, chabazite, etc " is mixed with water and an alkali metal base such as sodium hydroxide or a basic salt such as an alkali-mctal carbonate, borate, phosphate, silicate, etc., as an extrusion aid followed by mulling, extrudin~ and subsequently drying the extrudate. It is thought that substitution of alkali metal for hydro~en in the silanol groups on the surfaces of siliceous materials such as the foregoing zeolites is responsible for their improved crush strength~ The resulting extrudate is said to possess superior crush stren~th and sufficient integrity to withstand treatment with acids so that it is possible to steam, acid extract or calcine them. To avoid trapping the alkali ~etal of the extrusion aid in the extrudate, the alkali metal is ordinarily removed by exchange under acidic con~itions using dilute nitric acid in lM a~monium nitrate solution, The silica-bound zeolite catalyst of U,S. Patent No. 4,582,815 is lndicated to be useful in a rariety of hydrocarbon conversions including hydrocracking; isomerization3 ~3~
F-4513 ~~5~~
hydrogenation, dehydrogenation, polymerization, refor~ing, catalytic cracking and catalytic hydrocracking.
In the method for preparing a low acidity refractory oxide-bound zeolite cataly~st comFosition described in c~mmonl~
assigne~ copending Canadian patent application Serial No. 565,568, a homogeneous mixture of an intermediate pore size zeolite such as ZSML5 (ZSM~35 is also mentioned), water and a low acidity refractory oxide binder, e.g~, silica, which contains at least an extrusion-facilitating amount of the binder in a colloidal lo state and which is substantially free of adde~ alkali ~etal base and/or basic salt is formed into an extrudable mass, the mass is extruded and the extrudate is dried and calcined. The resulting catalyst is disclosed to be useful in the same sort of hydrocarbon conversion processes mentioned in U.S. Pate~t ~o. 4,582,8159 supra.
There is no reco~nition or appreciation in Ca~adian pa~ent application Serial No. 565,568 that a low acidity re~ractory oxi~e-bound intermediate pore size zeolite catalyst composition w 'l demons~rate improved activity and stability in a catalytic dewaxing operation co~pared with the same zeolite bound with alumina.
It has now been discovered that an intermediate pore size zeolite which has been bound with a low acidity refrac~,ory oxide binder material in the ~aM er disclosed in aforesaid Can~Ldlan p~en~
application Serial No. 565,568 when employed in the catalytic hydrodewaxin~ of a waxy hydrocarbon oil shows sigllificantly improved ~5 activity and stability in such an operation compared with the same type zeolite composited with an acidic binder material such as alumina.
Thus, in accordance with the present invention, a process for the catalytic hydrodewaxing of a waxy hydrocarbon fraction to provide a lubricating oil of high ~iscosi~y index is provided which comprises contacting such a fraction boiling within the approximate range of fro~ about 232C (450~ to about 566C (1053P) under catalytic hydrodewaxing conditions with an extruded low acidity ~3~7:~
refractory oxide-bound intermediate pore size zeolite dewaxin~
catalyst which has been prepared with at leas~ an extrusion facilitating a~ount of the refractory oxide in colloidal form in the presence or absence of a hydrogenation/dehydrogenation metal component to provide said high viscosity index lubricating oil.
Figs. 1 and 2 are graphic representations of the performance, respectively, of alumina-bound ZSM~35 (prior art) and low acidity silica-bound ZSM-35 (this invention) employed in the hydrodewaxing of a light neutral raffinate char~e stock under essentially the same hydrodewaxin~ conditions.
The intermediate pore size zeolite component of the catalyst composition employed in the hydrodewaxin~ process of the present invention possesses a pore dimension greater than about 5 Angstroms and a Constraint Index in the approxi~ate range of from about 1 to about 12~. Zeolites of this type can be na-tural, synthetic or a mixture of the two. Representative of the useful zeolites are zeolite ZSM~5 (I].S. Patent No. 3,102,886; Re. Z9,948), zeolite ZSM-ll (U.S. Patent No. 3,709,97919 zeolite ZS~ 12 (U.S.
Patent No. 3,832,449), zeolite ZSM-22 (C~nadian ~atent No. 1I227J.438)f ~eolite ZSM-23 (U.S~ Patent No 4,076,842) and Z.~M-.~5 (U.S. Patent No. 4~016,245). Of the foregoing, ZSM-35 is pre~erred.
The original cations associated with the zeolites utilized herein can be replaced by a wide variety of other cations according to techniques well known in the art. Typica~ replacing cations 2s include hydrogen, ammonium and metal cations and mixtures of the _ *Constraint Index is an art-recogni~ed way of characterizing the capability of a zeolite to provide constrained access of material ~o its pore structure and egress of material therefrom. For a detailed explanation of ~he significance of the Constraint Index and the manner by which it is determined for a particular zeolite, reference may be made9 inter_alia9 to ~e relevant disclosure in U.S. Patent No. 4,247~388 referred to above.
.
7~ ~
F-4513 ~~7~~
same. Of the replacing metallic cations, particular preference is given to cations o~ metals S13Ch as the rare earth metals, manganese, calcium, as well as metals of Group II of the Periodic Table, e.~., zinc, and Group VIII of the Periodic Table, e.g., nickel, platinum and palladium~
Typical ion exchange techniques involve contacting the particular zeolite with a salt of the desired replacin~ cation.
Although a wide variety of salts can be e~ployed, particular preference is given to chlorides, nitrates and sulfates.
Representative lon exchange techniques are disclosed in a variety of patents including U.S. Patent Nos. 3,140,249; 3,140,251;
and 3,140,253.
Following contact with a solution of the desired replacing cation, the zeolite is then preferably washed with water and dried at a temperature ranging from 65C ~150F) to about 316C (600F) and thereafter calcined in air or other inert ~as at temperatures ran~ing from abou~ 260C (500F~ to 816C (1500F) for periods of time ranging from 1 to 48 hours or more. Improved selectivity and other beneficial properties can be obtained by subjecting the zeolite to treatment with steam at elevated temperatures ran~in~
from 427C (800F) to 816C (1500P) and preferably 538C ~1000F) and 760C (1400F). The treatment can be accomplished in atmospheres of 100~ steam or an atmosphere consisting of steam and a gas which is substantially inert to the zeolites. A similar treat~ent can be accomplished at lower temperatures and elevated pressure, e.g., 177-371C (350-700F) at 1000 to 1480 kPa (10 to about 200 atmospheres).
The zeolite utilized in the process of this invention is desirably employed in intimate combination wi~h a hydrogenation-dehydrogenation component in an amount between about 0.1 and about 5 weight percent. Components of this type include tungsten, vanadium, zinc, molybdenum~ rhenium, nickel, cobalt7 chromium, manganese ~r a noble ~etal such as platinum or palladium.
F-~513 --8--Such component can be exchanged into the composition, impregnated thereon or physically intimately admixed therewith. Such co~ponent can be impregnated in or onto the zeolite such as, for example, in the case of platinum, by treatin~ the zeolite with a platinum metal-containing ion. Suitable platinum compounds include chloroplatinic acid, platinous chloride and various compounds containing the platinum complex. Platinum, palladium, zinc and nickel are preferred hydrogena~ion components.
The co~pounds of the useful platinum or other metals can be divided into compounds in which the metal is present in the cation of the compound and compounds in which it is present in the anion of the compound. Both types of compounds which contain the metal in ~he ionic state can be used. A solution in which platinum metal is in the form of a cation or cationic complex, e.g., Pt(NH2)4C12 is particularly useful Prior to use in catalytic hydrodewaxin~ , the zeolite shoul~ be dehydrated at least partially. This can be done by heating to a temperature in the range of 2000 to 600C in an inert atmosphere, such as air, nitrogen, etcO and at atmospheric or subatmospheric pressures for between 1 and 48 hours. Dehydration can also be perfor~ed at lower te~peratures merely by using a vacuum ~ut a lon~er time is required to obtain a sufficient degree of dehydration.
The hinder material herein can be selected from a~ong any of the low acidity refrac-tory oxides of metals of Groups IVA and IVB
of the Periodic Table o the Elements. Par-ticularly useful are the oxides of silicon, germanium, titanium and zirconium with silica being preferred. Combinations of such oxides with other oxides are also useful provided that at least about 40 weight pereent, and preferably at least 50 weight percent, of the total oxide is one or a co~bination of the aforesaid Group IYA and/or Group IVB metal oxides. Thus, mixtures of oxides which can be used to pro~ide the binder ~aterial herein include silica-alumina, silica-magn0sia~
F-4513 ~9~~
silica-zirconia, silica-thoria, silica beryllia, silica-titania~
titania-zirconia, silica-alumina-thoria, silica-alumina-zirconia, silica-alumina-~agnesia and silica-magnesia-7irconia.
In preparin~ ~he low acidity refractory oxide-bound intermediate pore zeolite catalyst employed herein, it is essential that the refractory oxide binder contain at least an extrusion-facilitating amount of the same or different low acidity refractory oxide binder in colloidal form. The colloidal Group IVA
and or Group IVB metal oxide component of the binder can represent anywhere from about 1 to about 90 wei~ht percent or more of the total binder. For example, in the case of silica, amounts of colloidal silica ranging from about 2 to about 60 weight percent of the total binder generally provide entirely acceptable results.
The relative proportions of zeolite and 1QW acidity refractory oxide binder on an anhydrous basis can vary widely with the zeolite content ranging from between about 1 to about 99 weight percent, and more usually in the range of from about 5 to about 80 weight percent, of the dry composite.
Fxtrudates of 1.6 mm (l/16 inch) typically have a crush strength of from about 22 to 107 N (5 to abou~ 24 po~ds) when the crushing force is applied over a 3.2 mm (1/8 inch) length. Crush strengths range from about 7 N/mm to 33.6 N/mm (40 to abou~ 192 lb/linear inch). In addition, the low acidity refractory oxide-bound extrudates ~not 100~ zeolite) are also characterized by a hi~h porosity, i.e., between about 0 43 and about 1 cc/gram (measured by mercury porosimeter and helium absorption).
The process of this inventlon is concerned with hydrodewaxing of hydrocarbon feedstocks includin~ petroleum as well as synthetic hydrocarbon feedstocks such as those resulting from the conversion of synthesis gas. The term '~ydrodewaxing" as used in the specification and claims is used in its ~roadest sense ~nd is intended ~o mean the removal of ~hose hydrocarbons which readily solidify ~waxes) from hydrocarbon stocks. Hydrocarboll feeds which Y~
can be treated include lubricating oil stocks as well as those which have a freeze point or pour point problem, i.e. stocks boiling above about 177~C (350F) such as whole crude, distillates, bri~ht stock9 etc.
~ydrodewaxing conditions include temperatures between about 260~C (500F) and about 538C (1000F), a pressure between about 690 (100) and about 20700 kPa (3000 psig) but preferably betwsen about 1480 and 4930 kPa (200 and about 700 psig~. The liquid hourly space velocity is ~enerally between about 0.1 and about 10, preferably between about 0.5 and about 4 and the hydrogen to hydrocarbon mole ratio is generally between about 1 and about 20, preferably between about 2 and about 10.
The following examples are illustrative of the catalytic hydrodewaxin~ process of this invention.
This example illustrates the preparation of a preferred zeolite component, Z~1-35 (see U.S. Patent No. 4,016,245 for more details), employing water, pyrrolidine, sodium hydroxide, aluminum sulfate and amorphous silica (PPG Industries HiSil 233 EP) in the following molar ratios SiO2/A120321 HzO/SiO2 22 OH/SiO20.38 % solids 12 The hydroxide concentration is based on inorganic sources only. The reaction mixture was crystallized in 92 hours in a stirred autoclave at 104C (220F). ~he zeolite was subsequently washed and dried at 121C (250F) overnight. ~hemical properties of the ~eolite are set forth in Table 1 as follows:
7~
P-~513 -~
Table l:Chemical Properties of ZSM-35 N, wt% 2.04 C, wt% 7.39 Na, wt% 1.2 SiO2, wt% 77.9 A120~. wt~ 6.4 Ash, ~% 87.6 Crystallinity, ~ 100 (ZSM-35 Standard) This example illustrates the prepara~ion of an alumina-bound ZSM-35 hydrodewaxing catalys~ similar to that described in U.SO Patent No. 4,372,839 employing the ZSM 35 of Examp'le 1.
The zeolite was mixed with alumina -to form a ~ixture of 65 parts (on a dry basis) zeolite and 35 parts alumina. Enough water was added to the mixture so that ~he resultirlg catalyst could ~e formed into 1.6 mm (1/16") extrudate. The extrudate was dried at lZlC (250F) and then calcined as follows: (i) 3 hours at 482~C
(900F) in flowing nitrogen, (ii) 1 hour at 482C (~OO~F) in a flowing 50 vol% nitrog~n/50 vol~ air mixture~ and (iii) 3 hours at 538C (lOGOF) in flowing airO The calcined catalyst was activated by aqueous exchanges with lN NH4N03 solution ~ollowing by drying at 121C (250~F) and calcining for 3 hours at 538C (1000F) in flowing air. Physical properties o~ the alumina-bound catalyst composltion are set forth in Table 2 as follows:
F-4513 ~-12-Table 2: Physical Properties of Alumina~Bound ZSM-35 Catalyst Alumina-Bound Z.S~-35 Alpha Value ** 82 Na, ppm ~75 Density, g/cc Real 2.60 Particle 0.88 Surface Area, m2/g 299 Pore Volume, cc/~ 0.75 This example illustrakes the preparation of a low acidi~y silica-bound ZSM-35 hydrodewaxing catalyst in accordallce with the present lnvention employing the ZSM-35 of Example 1.
Sixty five weight percent of Z~M-35 in the form of a powder was mixed with 35 weight percent (dry basis) of silica conslsting *~The alpha value, or alpha activi~y, is a measure o normal hexane cracking conversion relative to a silica-alumina cracking catalyst. The alpha test is described in a Letter to the Editor entitled l'Superactive Crystalline Alumi.nosilicate Hydrocarbon Cracking Catalyst~' by P~B. Weisz and JONO Mialeg Journal of Catalysis, 4, pp. 527~529 (1965~.
~ ~ Q ~t~
F-4513 -~13~-of a mixture of 17.5 weight percent amorphous precipitated silica (PPG Industries HiSil 233 ~P) and 17.5 weight percent colloidal silica (Ludox, HS-30). A homogeneous mix was obtained by mullin~.
The moisture content of the mix was adjusted to 42.5 weight percent with deionized water. After additional mulling, the resulting paste was extruded using a 50.8 m~ (2") Bo~lot extruder to yield a 1.6 mm (1/16") diameter extrudate. The extrudate was further processed in substantially the same manner as the aluminabound catalyst of Example 2. Physical properties of the silica-bound ZSM-35 catalyst are set forth in Table 3 as follows:
Table 3: Physical Properties of Silica-Bound ZSM-35 Catalyst Alpha Valve 105 Na, ppm 255 Dcnsity, g/cc Real 2.29 Particle 0.94 Surface Area, m2/g 279 Pore Volume, cc/g 0.62 EXAMPLE 4 (Comparison) The alumina-bound ZSM-35 catalyst of Example 2 was evaluated in the hydrodewaxing cf a light neutral raffinate carried "~ ~
J~
out at typical hydrodewaxing conditions, i.e., 1 LHSV, 2860 kPa (400 psig), and 71000 scf H2/B (2500 scf) H2/s. The physical properties of the raffinate are set forth in Table 4:
Table 4: Physical Properties of Light Neutral Raffinate Pour Point, C (F) D97 38 (1003 K.V. at 54C (100F,)cs D445-5 5.117 Gravity, API D1298~3 32~8 Sulfur, wt % 967-1 0.27 Nitrogen, ppm ~1208 18 Hydrogen, wt% M1252 14.24 Aniline Point, C (F) ~611 109 (228.0) CCR, wt~ D189 0.020 Distillation D1160-1 (vol ~ Distilled) IBP, 9C (F) 374 (706) 5~ 403 (757) 10% 410 (769) 30~ 425 (797) 50% 43~ (~20) 70% 455 t851) 80% 467 ~373) 90~ 481 (~98) 95% ~92 (917) EP 499 (931) The charge stock was introduced at 317C (5039F). After the first day-on~stream, a -1C (30F) pour lube product was obtained~ Attempting to make target pour lube prnduct 11.1 ~ 2.8C
(20 ~ 5F), ~he reactor temperature was increased by about 11C/day (20F/day) to a temperature of 340CC ~43F)~ As shown in Fig. 19 13~t7~
during this period, the lube pour point remained constant at -1.1C
(30F). Thereafter, the reactor temperature was maintained at 340C
~643F) for 10 days; the pour point increased at 0.5 1.1C/day (1-2F/day), At the end of the run, the reactor temperature was Yaried over a 44.4C (80F) temperature range in an sttempt to make a -6.7C (20F) lube product, target lube product could not be produced.
Table 5 belo~ sets forth the yields and properties of lube products obtained with unsteamed alu~ina-bo~ld ZSM-35 in accordance with this example.
Table 5: Yields and Properties of Lube Products Obtained With Uhsteamed Alumina-Bound ZSM-35 HDW Temp., C (F) 326 (618) 339 (643) H2 Pressure, kPa (psig) 2760 (400~ 2760 (400) Yields Pased on Wt % of Liquid Charge Cl-C5 ~.8 .5 4~5 3.0 2.2 C5's 2.2 1.5 C6-321C (610F) 4.9 3~4 321C~(610F~) 82 86 Paterial Balance, wt% 103 101 Lube Properties Pour Point, C (F) -1.1 (30) 7.2 (45) Cloud Point, C (F) 6.7 (44) 15.6 (60) Sulfur, wt% 0.30 0.31 Ni~rogen~ ppm 18 18 ~3 I;P6~
The silica-bound ZSM-35 hydrodewaxing catalyst of Example 3 was evaluated with the same li~ht neutral raffinate of Example 4 and under essentially the same processing conditions employed in that example. The charge stock was introduced at 319C (607F). As shown in Fig. 2, the silica-bound ZSM-35 was able to produce -6.7 208~C (20 ~ 5F) pour lube product for more than 21 days on stream.
Table 6 below sets forth the yields ~nd properties of lube products obtained with unsteamed silica-bound ZS~-35 in accordance with this example.
Table 6: Yields and Properties of Lube Products Obtained With Unsteamed Silica-Bound ZSM-35 ~W Temp., C ~F) 319 (607) 321 (610) H2 Pressure, kPa (psig) 2760 (4^0) 2760 (400) LHSV 1.07 1.02 Yields Based on Wt % of Liquid Char~e Cl-C~ 8~9 9,~
C4's 3.7 3.1 C5's 2.6 2.0 C6-321C (610~) 3.~ 3.5 321C (610F ) 82 82 M~terial ~alance, wt~ 97 100 Lube Properties Pour Point, C (F) 6.7 (20) -3.9 ~25) Cloud Point, C (P) -1.1 (30~ 0 ~32) Sulfur, wt~ 0.32 0.34 Nitrogen, pp~ 25 26 ~3~ 7~&~
As shown by the performance data plotted in Figs. 1 and 2, while the alumina-bound ZS~-35 irreversibly aged at 0.5~1,1C/day (1-2F/day), the silica-bound ZSM-35 catalyst aged irreversibly at ~0.1C/day (~0.2F/day). And while the alu~ina-bound ZSM-35 was unable to produce a~-1.1C (~30)F pour lube product, such a product was obtained with the silica-bound ZSM-35.
As one would expect, when used in a hydrodewaxing operation under conditions such as those given above, a bound ZSM-35, irrespective of the nature of the binder, will generally provide lube products of hi~her V.I~ than that with the corresponding bound ZS~5 catalyst. Thus, a silica-bound ZSM-35 prepared in accordance with this invention and an al~mina bound ZSM-35 catalyst when both used in such an operation will demonstrate this expected increase in V.I. However, compared to the alumina-bound ZSM-35, the silica-bo~d ZSM-35 additionally demonstrates significantly greater stability and longer catalyst life.
This invention relates to a process for ~he catalytic hydrodewaxing of a waxy hydrocarbon oil to provide a lubricating oil of high viscosity index (V.I.) The invention is specifically directed to a process for catalytically hydrodewaxing a waxy distillate lubricating oil utilizing a low acidity refractory oxide-bo~d intermediate pore size zeolite, e.g., silica-bound ZSM-5 or silica-bound ZSM~35, to obtain a lubricating oil of low pour point and of high V,I, Refining suitable petroleum crude oils to obtain a variety of lubricating oils which function effectively in diverse environments has become a highly developed and complex art.
Although the broad principles involved in refining are qualitatively understood, the art is encumbered by quantitatiYe uncertainties which require considerable resor-t to empiricism in practical practical refining. Underlying these quantitative uncertainties is the complexity of the molecular constitution of lubricating oils.
Because lubricating oils for the most part are based on petroleum fractions boiling above about 232C (450F), the molecular weight of the hydrocarbon constituents is high and these constituen~s display almost all conceivable structure types. lhis complexity and its consequences are referred to in we11 known treatises, such as, for example, in "Petroleum Refinery Engineering,'7 by WoL~ Nelson, ~cGraw Hill Book Company, IncO, ~ew York, N~Y~s 1958 (Fourth Edition).
In general, the basic premise in lubricant refining is that a suitable crude oil, as shown by experience or by assay, contains a quantity o lubricant stock having a predetermined set of properties ~3~ 7 3L~
such as, for example, appropriate viscosity, oxidation stability, and ~aintenance of fluidity at low temperatures. The process of refining to isolate that lubricant stock consists of a set of subtractive unit operations which removes the unwanted components.
The most important of these unit operations include distillation, solvent refining, and dewaxing, which basically are physical separation processes in the sense that if all the separated fractions were recombined one would reconstitute ~he crude oil.
A refined lubricant stock may be used as such as a lubricant, or it may be blended with another refined lubricant stock having different properties. Or, the refined lubricant stock9 prior to use as a lubricant, may be co~pounded with one or more additives which function~ for example, as antioxidants, extre~e pressure additives, and V.I. improvers.
For the preparation of a hi~h ~rade distillate lubricating oil stock, the current practice is to vacuum distill an atmospheric tower residuum from an appropriate crude oil as the first step.
This step provides one or more raw stocks within the boiling ran~e of about 232C (450) to 566C (1050F) Ater preparation of a raw stock of sui-table boilin~ range, it is extracted with a solvent, e.g., furfural, phenol, sulfalane, or chlorex7 which is selective for aromatic hydrocarbons, and which reinoves undesirable components. The raffina-te from solvent refining is then dewaxed, for example by ad~ixing with a solvent such as a blend of methyl ethyl ketone and toluene. The mixture is chilled to induce crystallization of the paraffin waxes which are then separated from the raffinate. Sufficient quanti~ies of wax are removed to provide the desired pour point for the raffinate.
Other processes such as hydrofinishing or clay percolation may be used if needed to reduce the nitrogen and sulfur conten~s or improve the color of the lubricating oil stock.
Viscosity index (V.I.) is a quality parameter of considerable importance Eor distillate lubricating oils to be used F-4513 ~~3~~
in aUtQmotiVe engines and aircraft engines which are subject to wide variations in temperature. This Index indicates the rate of change of viscosity with temperature. A high viscosity lndex of 100 indicates an oil that does not tend to become viscous at low temperatures or become thin at hi~h temperatures. ~asuremen~ of the Saybolt Uhiversal Viscosity of an oil at 54 (130) and 38~C
(~00F), and referral to correlations, provides 3 measure of the V.I. of the oil. For purposes of the present invention, whenever V.I. is referred to it is meant the V.I. as noted in the Viscosity Index tabulations of the ASI~I (D567), published by AST~, 1916 Race St., Philadelphia 3, Pa., or equivalent.
To prepare high V.I. automotive and aircraft oils the refiner usually selects a crude oil relatively rich in paraffin hydrocarbons, since experience has shown that crudes poor in paraffins, such as those commonly termed "naphthene base" crudes, yield little or no refined stock having a V I. above about 40.
Suitable st^cks for high V.I. oils, however, also contain substantial quantities of w~xes which result in solvent-refined lubricating oil stocks of high pour point. Thus, in general9 the refining of crude oil to prepare acceptable high V.I. distillate stocks ordinarily includes dewaxing to reduce the pour point~
In recent years, catalytic techniques have become available for dewaxing of petroleum stocks. Catalytic dewaxing9 unlike prior-art dewaxing processes, although subtractive, is not a physical process but ra-ther depends on transforming the straight chain and other waxy paraffins to nonwax materials. The process, however9 is ~ore economical and thus of industrial interest even thou~h at leas~ some loss of se~lable wax is inherent. Com~ercial interest in catalytic dewaxlng is evidence of the need for more 3~ efficient refinery processes to produce low pour point lubricantsO
UOS. Reissue Patent No. 28~398 describes a process for catalytic dewaxing with a catalyst comprising zeolite ZSM-5~ Such a process combined with catalytic hydrofinishing is described in VOS~
~3~P6~7~6 Patent No. 3,894,938. U.S~ Patent No. 3,755,138 describes a process for mild solvent dewaxing to remove hi~h quality wax from a lube stock, which is then catalytically dewaxed to specification pour point. U.S. Patent No. 4,2229855 describes dewaxing operations to produce lubricating oils of low pour point and of high V.I~
utilizin~ a special class of zeolites which includes ZSM-23 and ~SM~35.
U.S. Patent No. 4,247,388 describes dewaxing operations utilizing ZSM'5 type zeolites of specific activity.
U.S. Patent No. 4,372,839 describes a catalytic dewaxing process employing two different zeolites such as ZSY~5 and ZSM-35.
U.S. Patent No. 4,5829815 describes a method for prep~ring a silica-bound zeolite of improved crush stren~th relative to other silica-rich zeolites. Accordin~ to this method, a ~ixture of silica and a zeolite su~h as ZSM~4 (Omega), ZSM-5, ZS~-ll, ZSM-12, ZSM-23, ZS~-35, ZSM-38, ZSM-48, ~eta, X, Y, L, ferrierite, ~ordenite, dachiardite, clinoptilolite, offretite, erionite, ~melinite, chabazite, etc " is mixed with water and an alkali metal base such as sodium hydroxide or a basic salt such as an alkali-mctal carbonate, borate, phosphate, silicate, etc., as an extrusion aid followed by mulling, extrudin~ and subsequently drying the extrudate. It is thought that substitution of alkali metal for hydro~en in the silanol groups on the surfaces of siliceous materials such as the foregoing zeolites is responsible for their improved crush strength~ The resulting extrudate is said to possess superior crush stren~th and sufficient integrity to withstand treatment with acids so that it is possible to steam, acid extract or calcine them. To avoid trapping the alkali ~etal of the extrusion aid in the extrudate, the alkali metal is ordinarily removed by exchange under acidic con~itions using dilute nitric acid in lM a~monium nitrate solution, The silica-bound zeolite catalyst of U,S. Patent No. 4,582,815 is lndicated to be useful in a rariety of hydrocarbon conversions including hydrocracking; isomerization3 ~3~
F-4513 ~~5~~
hydrogenation, dehydrogenation, polymerization, refor~ing, catalytic cracking and catalytic hydrocracking.
In the method for preparing a low acidity refractory oxide-bound zeolite cataly~st comFosition described in c~mmonl~
assigne~ copending Canadian patent application Serial No. 565,568, a homogeneous mixture of an intermediate pore size zeolite such as ZSML5 (ZSM~35 is also mentioned), water and a low acidity refractory oxide binder, e.g~, silica, which contains at least an extrusion-facilitating amount of the binder in a colloidal lo state and which is substantially free of adde~ alkali ~etal base and/or basic salt is formed into an extrudable mass, the mass is extruded and the extrudate is dried and calcined. The resulting catalyst is disclosed to be useful in the same sort of hydrocarbon conversion processes mentioned in U.S. Pate~t ~o. 4,582,8159 supra.
There is no reco~nition or appreciation in Ca~adian pa~ent application Serial No. 565,568 that a low acidity re~ractory oxi~e-bound intermediate pore size zeolite catalyst composition w 'l demons~rate improved activity and stability in a catalytic dewaxing operation co~pared with the same zeolite bound with alumina.
It has now been discovered that an intermediate pore size zeolite which has been bound with a low acidity refrac~,ory oxide binder material in the ~aM er disclosed in aforesaid Can~Ldlan p~en~
application Serial No. 565,568 when employed in the catalytic hydrodewaxin~ of a waxy hydrocarbon oil shows sigllificantly improved ~5 activity and stability in such an operation compared with the same type zeolite composited with an acidic binder material such as alumina.
Thus, in accordance with the present invention, a process for the catalytic hydrodewaxing of a waxy hydrocarbon fraction to provide a lubricating oil of high ~iscosi~y index is provided which comprises contacting such a fraction boiling within the approximate range of fro~ about 232C (450~ to about 566C (1053P) under catalytic hydrodewaxing conditions with an extruded low acidity ~3~7:~
refractory oxide-bound intermediate pore size zeolite dewaxin~
catalyst which has been prepared with at leas~ an extrusion facilitating a~ount of the refractory oxide in colloidal form in the presence or absence of a hydrogenation/dehydrogenation metal component to provide said high viscosity index lubricating oil.
Figs. 1 and 2 are graphic representations of the performance, respectively, of alumina-bound ZSM~35 (prior art) and low acidity silica-bound ZSM-35 (this invention) employed in the hydrodewaxing of a light neutral raffinate char~e stock under essentially the same hydrodewaxin~ conditions.
The intermediate pore size zeolite component of the catalyst composition employed in the hydrodewaxin~ process of the present invention possesses a pore dimension greater than about 5 Angstroms and a Constraint Index in the approxi~ate range of from about 1 to about 12~. Zeolites of this type can be na-tural, synthetic or a mixture of the two. Representative of the useful zeolites are zeolite ZSM~5 (I].S. Patent No. 3,102,886; Re. Z9,948), zeolite ZSM-ll (U.S. Patent No. 3,709,97919 zeolite ZS~ 12 (U.S.
Patent No. 3,832,449), zeolite ZSM-22 (C~nadian ~atent No. 1I227J.438)f ~eolite ZSM-23 (U.S~ Patent No 4,076,842) and Z.~M-.~5 (U.S. Patent No. 4~016,245). Of the foregoing, ZSM-35 is pre~erred.
The original cations associated with the zeolites utilized herein can be replaced by a wide variety of other cations according to techniques well known in the art. Typica~ replacing cations 2s include hydrogen, ammonium and metal cations and mixtures of the _ *Constraint Index is an art-recogni~ed way of characterizing the capability of a zeolite to provide constrained access of material ~o its pore structure and egress of material therefrom. For a detailed explanation of ~he significance of the Constraint Index and the manner by which it is determined for a particular zeolite, reference may be made9 inter_alia9 to ~e relevant disclosure in U.S. Patent No. 4,247~388 referred to above.
.
7~ ~
F-4513 ~~7~~
same. Of the replacing metallic cations, particular preference is given to cations o~ metals S13Ch as the rare earth metals, manganese, calcium, as well as metals of Group II of the Periodic Table, e.~., zinc, and Group VIII of the Periodic Table, e.g., nickel, platinum and palladium~
Typical ion exchange techniques involve contacting the particular zeolite with a salt of the desired replacin~ cation.
Although a wide variety of salts can be e~ployed, particular preference is given to chlorides, nitrates and sulfates.
Representative lon exchange techniques are disclosed in a variety of patents including U.S. Patent Nos. 3,140,249; 3,140,251;
and 3,140,253.
Following contact with a solution of the desired replacing cation, the zeolite is then preferably washed with water and dried at a temperature ranging from 65C ~150F) to about 316C (600F) and thereafter calcined in air or other inert ~as at temperatures ran~ing from abou~ 260C (500F~ to 816C (1500F) for periods of time ranging from 1 to 48 hours or more. Improved selectivity and other beneficial properties can be obtained by subjecting the zeolite to treatment with steam at elevated temperatures ran~in~
from 427C (800F) to 816C (1500P) and preferably 538C ~1000F) and 760C (1400F). The treatment can be accomplished in atmospheres of 100~ steam or an atmosphere consisting of steam and a gas which is substantially inert to the zeolites. A similar treat~ent can be accomplished at lower temperatures and elevated pressure, e.g., 177-371C (350-700F) at 1000 to 1480 kPa (10 to about 200 atmospheres).
The zeolite utilized in the process of this invention is desirably employed in intimate combination wi~h a hydrogenation-dehydrogenation component in an amount between about 0.1 and about 5 weight percent. Components of this type include tungsten, vanadium, zinc, molybdenum~ rhenium, nickel, cobalt7 chromium, manganese ~r a noble ~etal such as platinum or palladium.
F-~513 --8--Such component can be exchanged into the composition, impregnated thereon or physically intimately admixed therewith. Such co~ponent can be impregnated in or onto the zeolite such as, for example, in the case of platinum, by treatin~ the zeolite with a platinum metal-containing ion. Suitable platinum compounds include chloroplatinic acid, platinous chloride and various compounds containing the platinum complex. Platinum, palladium, zinc and nickel are preferred hydrogena~ion components.
The co~pounds of the useful platinum or other metals can be divided into compounds in which the metal is present in the cation of the compound and compounds in which it is present in the anion of the compound. Both types of compounds which contain the metal in ~he ionic state can be used. A solution in which platinum metal is in the form of a cation or cationic complex, e.g., Pt(NH2)4C12 is particularly useful Prior to use in catalytic hydrodewaxin~ , the zeolite shoul~ be dehydrated at least partially. This can be done by heating to a temperature in the range of 2000 to 600C in an inert atmosphere, such as air, nitrogen, etcO and at atmospheric or subatmospheric pressures for between 1 and 48 hours. Dehydration can also be perfor~ed at lower te~peratures merely by using a vacuum ~ut a lon~er time is required to obtain a sufficient degree of dehydration.
The hinder material herein can be selected from a~ong any of the low acidity refrac-tory oxides of metals of Groups IVA and IVB
of the Periodic Table o the Elements. Par-ticularly useful are the oxides of silicon, germanium, titanium and zirconium with silica being preferred. Combinations of such oxides with other oxides are also useful provided that at least about 40 weight pereent, and preferably at least 50 weight percent, of the total oxide is one or a co~bination of the aforesaid Group IYA and/or Group IVB metal oxides. Thus, mixtures of oxides which can be used to pro~ide the binder ~aterial herein include silica-alumina, silica-magn0sia~
F-4513 ~9~~
silica-zirconia, silica-thoria, silica beryllia, silica-titania~
titania-zirconia, silica-alumina-thoria, silica-alumina-zirconia, silica-alumina-~agnesia and silica-magnesia-7irconia.
In preparin~ ~he low acidity refractory oxide-bound intermediate pore zeolite catalyst employed herein, it is essential that the refractory oxide binder contain at least an extrusion-facilitating amount of the same or different low acidity refractory oxide binder in colloidal form. The colloidal Group IVA
and or Group IVB metal oxide component of the binder can represent anywhere from about 1 to about 90 wei~ht percent or more of the total binder. For example, in the case of silica, amounts of colloidal silica ranging from about 2 to about 60 weight percent of the total binder generally provide entirely acceptable results.
The relative proportions of zeolite and 1QW acidity refractory oxide binder on an anhydrous basis can vary widely with the zeolite content ranging from between about 1 to about 99 weight percent, and more usually in the range of from about 5 to about 80 weight percent, of the dry composite.
Fxtrudates of 1.6 mm (l/16 inch) typically have a crush strength of from about 22 to 107 N (5 to abou~ 24 po~ds) when the crushing force is applied over a 3.2 mm (1/8 inch) length. Crush strengths range from about 7 N/mm to 33.6 N/mm (40 to abou~ 192 lb/linear inch). In addition, the low acidity refractory oxide-bound extrudates ~not 100~ zeolite) are also characterized by a hi~h porosity, i.e., between about 0 43 and about 1 cc/gram (measured by mercury porosimeter and helium absorption).
The process of this inventlon is concerned with hydrodewaxing of hydrocarbon feedstocks includin~ petroleum as well as synthetic hydrocarbon feedstocks such as those resulting from the conversion of synthesis gas. The term '~ydrodewaxing" as used in the specification and claims is used in its ~roadest sense ~nd is intended ~o mean the removal of ~hose hydrocarbons which readily solidify ~waxes) from hydrocarbon stocks. Hydrocarboll feeds which Y~
can be treated include lubricating oil stocks as well as those which have a freeze point or pour point problem, i.e. stocks boiling above about 177~C (350F) such as whole crude, distillates, bri~ht stock9 etc.
~ydrodewaxing conditions include temperatures between about 260~C (500F) and about 538C (1000F), a pressure between about 690 (100) and about 20700 kPa (3000 psig) but preferably betwsen about 1480 and 4930 kPa (200 and about 700 psig~. The liquid hourly space velocity is ~enerally between about 0.1 and about 10, preferably between about 0.5 and about 4 and the hydrogen to hydrocarbon mole ratio is generally between about 1 and about 20, preferably between about 2 and about 10.
The following examples are illustrative of the catalytic hydrodewaxin~ process of this invention.
This example illustrates the preparation of a preferred zeolite component, Z~1-35 (see U.S. Patent No. 4,016,245 for more details), employing water, pyrrolidine, sodium hydroxide, aluminum sulfate and amorphous silica (PPG Industries HiSil 233 EP) in the following molar ratios SiO2/A120321 HzO/SiO2 22 OH/SiO20.38 % solids 12 The hydroxide concentration is based on inorganic sources only. The reaction mixture was crystallized in 92 hours in a stirred autoclave at 104C (220F). ~he zeolite was subsequently washed and dried at 121C (250F) overnight. ~hemical properties of the ~eolite are set forth in Table 1 as follows:
7~
P-~513 -~
Table l:Chemical Properties of ZSM-35 N, wt% 2.04 C, wt% 7.39 Na, wt% 1.2 SiO2, wt% 77.9 A120~. wt~ 6.4 Ash, ~% 87.6 Crystallinity, ~ 100 (ZSM-35 Standard) This example illustrates the prepara~ion of an alumina-bound ZSM-35 hydrodewaxing catalys~ similar to that described in U.SO Patent No. 4,372,839 employing the ZSM 35 of Examp'le 1.
The zeolite was mixed with alumina -to form a ~ixture of 65 parts (on a dry basis) zeolite and 35 parts alumina. Enough water was added to the mixture so that ~he resultirlg catalyst could ~e formed into 1.6 mm (1/16") extrudate. The extrudate was dried at lZlC (250F) and then calcined as follows: (i) 3 hours at 482~C
(900F) in flowing nitrogen, (ii) 1 hour at 482C (~OO~F) in a flowing 50 vol% nitrog~n/50 vol~ air mixture~ and (iii) 3 hours at 538C (lOGOF) in flowing airO The calcined catalyst was activated by aqueous exchanges with lN NH4N03 solution ~ollowing by drying at 121C (250~F) and calcining for 3 hours at 538C (1000F) in flowing air. Physical properties o~ the alumina-bound catalyst composltion are set forth in Table 2 as follows:
F-4513 ~-12-Table 2: Physical Properties of Alumina~Bound ZSM-35 Catalyst Alumina-Bound Z.S~-35 Alpha Value ** 82 Na, ppm ~75 Density, g/cc Real 2.60 Particle 0.88 Surface Area, m2/g 299 Pore Volume, cc/~ 0.75 This example illustrakes the preparation of a low acidi~y silica-bound ZSM-35 hydrodewaxing catalyst in accordallce with the present lnvention employing the ZSM-35 of Example 1.
Sixty five weight percent of Z~M-35 in the form of a powder was mixed with 35 weight percent (dry basis) of silica conslsting *~The alpha value, or alpha activi~y, is a measure o normal hexane cracking conversion relative to a silica-alumina cracking catalyst. The alpha test is described in a Letter to the Editor entitled l'Superactive Crystalline Alumi.nosilicate Hydrocarbon Cracking Catalyst~' by P~B. Weisz and JONO Mialeg Journal of Catalysis, 4, pp. 527~529 (1965~.
~ ~ Q ~t~
F-4513 -~13~-of a mixture of 17.5 weight percent amorphous precipitated silica (PPG Industries HiSil 233 ~P) and 17.5 weight percent colloidal silica (Ludox, HS-30). A homogeneous mix was obtained by mullin~.
The moisture content of the mix was adjusted to 42.5 weight percent with deionized water. After additional mulling, the resulting paste was extruded using a 50.8 m~ (2") Bo~lot extruder to yield a 1.6 mm (1/16") diameter extrudate. The extrudate was further processed in substantially the same manner as the aluminabound catalyst of Example 2. Physical properties of the silica-bound ZSM-35 catalyst are set forth in Table 3 as follows:
Table 3: Physical Properties of Silica-Bound ZSM-35 Catalyst Alpha Valve 105 Na, ppm 255 Dcnsity, g/cc Real 2.29 Particle 0.94 Surface Area, m2/g 279 Pore Volume, cc/g 0.62 EXAMPLE 4 (Comparison) The alumina-bound ZSM-35 catalyst of Example 2 was evaluated in the hydrodewaxing cf a light neutral raffinate carried "~ ~
J~
out at typical hydrodewaxing conditions, i.e., 1 LHSV, 2860 kPa (400 psig), and 71000 scf H2/B (2500 scf) H2/s. The physical properties of the raffinate are set forth in Table 4:
Table 4: Physical Properties of Light Neutral Raffinate Pour Point, C (F) D97 38 (1003 K.V. at 54C (100F,)cs D445-5 5.117 Gravity, API D1298~3 32~8 Sulfur, wt % 967-1 0.27 Nitrogen, ppm ~1208 18 Hydrogen, wt% M1252 14.24 Aniline Point, C (F) ~611 109 (228.0) CCR, wt~ D189 0.020 Distillation D1160-1 (vol ~ Distilled) IBP, 9C (F) 374 (706) 5~ 403 (757) 10% 410 (769) 30~ 425 (797) 50% 43~ (~20) 70% 455 t851) 80% 467 ~373) 90~ 481 (~98) 95% ~92 (917) EP 499 (931) The charge stock was introduced at 317C (5039F). After the first day-on~stream, a -1C (30F) pour lube product was obtained~ Attempting to make target pour lube prnduct 11.1 ~ 2.8C
(20 ~ 5F), ~he reactor temperature was increased by about 11C/day (20F/day) to a temperature of 340CC ~43F)~ As shown in Fig. 19 13~t7~
during this period, the lube pour point remained constant at -1.1C
(30F). Thereafter, the reactor temperature was maintained at 340C
~643F) for 10 days; the pour point increased at 0.5 1.1C/day (1-2F/day), At the end of the run, the reactor temperature was Yaried over a 44.4C (80F) temperature range in an sttempt to make a -6.7C (20F) lube product, target lube product could not be produced.
Table 5 belo~ sets forth the yields and properties of lube products obtained with unsteamed alu~ina-bo~ld ZSM-35 in accordance with this example.
Table 5: Yields and Properties of Lube Products Obtained With Uhsteamed Alumina-Bound ZSM-35 HDW Temp., C (F) 326 (618) 339 (643) H2 Pressure, kPa (psig) 2760 (400~ 2760 (400) Yields Pased on Wt % of Liquid Charge Cl-C5 ~.8 .5 4~5 3.0 2.2 C5's 2.2 1.5 C6-321C (610F) 4.9 3~4 321C~(610F~) 82 86 Paterial Balance, wt% 103 101 Lube Properties Pour Point, C (F) -1.1 (30) 7.2 (45) Cloud Point, C (F) 6.7 (44) 15.6 (60) Sulfur, wt% 0.30 0.31 Ni~rogen~ ppm 18 18 ~3 I;P6~
The silica-bound ZSM-35 hydrodewaxing catalyst of Example 3 was evaluated with the same li~ht neutral raffinate of Example 4 and under essentially the same processing conditions employed in that example. The charge stock was introduced at 319C (607F). As shown in Fig. 2, the silica-bound ZSM-35 was able to produce -6.7 208~C (20 ~ 5F) pour lube product for more than 21 days on stream.
Table 6 below sets forth the yields ~nd properties of lube products obtained with unsteamed silica-bound ZS~-35 in accordance with this example.
Table 6: Yields and Properties of Lube Products Obtained With Unsteamed Silica-Bound ZSM-35 ~W Temp., C ~F) 319 (607) 321 (610) H2 Pressure, kPa (psig) 2760 (4^0) 2760 (400) LHSV 1.07 1.02 Yields Based on Wt % of Liquid Char~e Cl-C~ 8~9 9,~
C4's 3.7 3.1 C5's 2.6 2.0 C6-321C (610~) 3.~ 3.5 321C (610F ) 82 82 M~terial ~alance, wt~ 97 100 Lube Properties Pour Point, C (F) 6.7 (20) -3.9 ~25) Cloud Point, C (P) -1.1 (30~ 0 ~32) Sulfur, wt~ 0.32 0.34 Nitrogen, pp~ 25 26 ~3~ 7~&~
As shown by the performance data plotted in Figs. 1 and 2, while the alumina-bound ZS~-35 irreversibly aged at 0.5~1,1C/day (1-2F/day), the silica-bound ZSM-35 catalyst aged irreversibly at ~0.1C/day (~0.2F/day). And while the alu~ina-bound ZSM-35 was unable to produce a~-1.1C (~30)F pour lube product, such a product was obtained with the silica-bound ZSM-35.
As one would expect, when used in a hydrodewaxing operation under conditions such as those given above, a bound ZSM-35, irrespective of the nature of the binder, will generally provide lube products of hi~her V.I~ than that with the corresponding bound ZS~5 catalyst. Thus, a silica-bound ZSM-35 prepared in accordance with this invention and an al~mina bound ZSM-35 catalyst when both used in such an operation will demonstrate this expected increase in V.I. However, compared to the alumina-bound ZSM-35, the silica-bo~d ZSM-35 additionally demonstrates significantly greater stability and longer catalyst life.
Claims (10)
1. A catalytic hydrodewaxing process which comprises contacting a waxy hydrocarbon feed with an extruded low acidity refractory oxide-bound intermediate pore size catalyst composition under hydrodewaxing conditions to provide a lube product, said catalyst composition being prepared with at least an extrusion facilitating amount of low acidity refractory oxide in colloidal form and demonstrating significantly increased stability and activity in such process compared to the same zeolite bound with an acidic binder material,
2. The process of Claim 1 wherein the low acidity refractory oxide is an oxide of a metal wherin said metal is selected from the group consisting of metals of Group IVA and/or and Group IVB of the Periodic Table of the Elements.
3. The process of Claim 2 wherein the metal is silicon, germanium, titanium and/or zirconium.
4. The process of Claim 2 wherein the zeolite is bound with a composition containing at least about 20 weight percent of said low acidity refractory oxide.
5. The process of Claim 2 wherein the zeolite is bound with a composition containing at least about 50 weight percent of said low acidity refractory oxide.
6. The process of Claim 4 wherein the zeolite is bound with a mixture of low acidity refractory oxide and acidic refractory oxide.
7. The process of Claim 5 wherein the zeolite is bound with a mixture of low acidity refractory oxide and acidic refractory oxide.
8. The process of Claim 1 wherein the intermediate pore size zeolite is selected from the group consisting of ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23 and ZSM-35.
9. The process of Claim 1 wherein the zeolite is associated with a hydrogenation-dehydrogenation metal species.
10. The process of claim 6 wherein the metal species is nickel.
3177h/0378h
3177h/0378h
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US11132487A | 1987-10-22 | 1987-10-22 | |
| US111,324 | 1987-10-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1306716C true CA1306716C (en) | 1992-08-25 |
Family
ID=22337851
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000580804A Expired - Lifetime CA1306716C (en) | 1987-10-22 | 1988-10-20 | Catalytic hydrodewaxing process |
Country Status (10)
| Country | Link |
|---|---|
| EP (1) | EP0313276B1 (en) |
| JP (1) | JP2609467B2 (en) |
| CN (1) | CN1015375B (en) |
| AU (1) | AU615679B2 (en) |
| CA (1) | CA1306716C (en) |
| DE (1) | DE3861759D1 (en) |
| ES (1) | ES2021145B3 (en) |
| FI (1) | FI92559C (en) |
| IN (1) | IN171776B (en) |
| ZA (1) | ZA887901B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| MY125670A (en) * | 1995-06-13 | 2006-08-30 | Shell Int Research | Catalytic dewaxing process and catalyst composition |
| US5951847A (en) * | 1995-11-09 | 1999-09-14 | Shell Oil Company | Catalytic dehazing of lubricating base oils |
| ES2198975T3 (en) * | 1998-11-18 | 2004-02-01 | Shell Internationale Research Maatschappij B.V. | PROCEDURE OF CATALYTIC DEPARAFINING. |
| KR100405831B1 (en) * | 2000-11-13 | 2003-11-14 | 최원태 | Double pipe leakage control packing |
| US20110124934A1 (en) * | 2008-06-06 | 2011-05-26 | Total Petrochemicals Research Feluy | Process for Making Crystalline Metallosilicates |
| EP2130586A1 (en) * | 2008-06-06 | 2009-12-09 | Total Petrochemicals Research Feluy | Process for making crystalline metallosilicates |
| US8394255B2 (en) * | 2008-12-31 | 2013-03-12 | Exxonmobil Research And Engineering Company | Integrated hydrocracking and dewaxing of hydrocarbons |
| US8617383B2 (en) * | 2010-06-29 | 2013-12-31 | Exxonmobil Research And Engineering Company | Integrated hydrocracking and dewaxing of hydrocarbons |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4247388A (en) * | 1979-06-27 | 1981-01-27 | Mobil Oil Corporation | Hydrodewaxing catalyst performance |
| US4437976A (en) * | 1981-08-07 | 1984-03-20 | Mobil Oil Corporation | Two-stage hydrocarbon dewaxing hydrotreating process |
| US4665265A (en) * | 1984-06-13 | 1987-05-12 | Mobil Oil Corporation | Conversion of olefins and paraffins over novel catalyst composition |
| US4582815A (en) * | 1984-07-06 | 1986-04-15 | Mobil Oil Corporation | Extrusion of silica-rich solids |
| ZA883091B (en) * | 1987-05-01 | 1989-12-27 | Mobil Oil Corp | Method for preparing a zeolite catalyst bound with a refractory oxide of low acidity |
-
1988
- 1988-10-10 IN IN707/MAS/88A patent/IN171776B/en unknown
- 1988-10-14 DE DE8888309642T patent/DE3861759D1/en not_active Expired - Lifetime
- 1988-10-14 EP EP88309642A patent/EP0313276B1/en not_active Expired - Lifetime
- 1988-10-14 ES ES88309642T patent/ES2021145B3/en not_active Expired - Lifetime
- 1988-10-20 CA CA000580804A patent/CA1306716C/en not_active Expired - Lifetime
- 1988-10-21 AU AU24144/88A patent/AU615679B2/en not_active Expired
- 1988-10-21 JP JP63267007A patent/JP2609467B2/en not_active Expired - Lifetime
- 1988-10-21 FI FI884884A patent/FI92559C/en not_active IP Right Cessation
- 1988-10-21 ZA ZA887901A patent/ZA887901B/en unknown
- 1988-10-21 CN CN88107267A patent/CN1015375B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| CN1015375B (en) | 1992-02-05 |
| EP0313276A1 (en) | 1989-04-26 |
| EP0313276B1 (en) | 1991-02-06 |
| ES2021145B3 (en) | 1991-10-16 |
| FI92559B (en) | 1994-08-31 |
| FI92559C (en) | 1994-12-12 |
| CN1032810A (en) | 1989-05-10 |
| FI884884A0 (en) | 1988-10-21 |
| AU2414488A (en) | 1989-04-27 |
| AU615679B2 (en) | 1991-10-10 |
| JPH01152189A (en) | 1989-06-14 |
| FI884884A (en) | 1989-04-23 |
| IN171776B (en) | 1993-01-02 |
| JP2609467B2 (en) | 1997-05-14 |
| DE3861759D1 (en) | 1991-03-14 |
| ZA887901B (en) | 1990-06-27 |
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